Capacitive Touch Panel

ABSTRACT

An integrally-formed capacitive touch panel is disclosed including: a singular lens substrate, a mask layer, and a sensing circuit integrally coupled with said singular lens substrate. Said singular lens substrate, said mask layer, and said sensing circuit are integrally formed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Prior Application No. 12/371,983, filed on Feb. 17, 2009, which claims priority from TW97202841, filed on Feb. 18, 2008 by the present inventor, the disclosure of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a touch panel, especially to a capacitive touch panel assembled with a display panel.

2. Description of the Related Art

Most electronic devices, such as PDA, palm-sized PC and information appliance, have a touch display panels. The touch display panel includes a lens, a display panel and a touch panel arranged between the lens and the display panel the prior art, the lens and the touch panel are separately formed on different substrates, which are usually glass substrates. The lens and the touch panel are then laminated to form a touch module. The touch module is further stacked up with and attached to the display panel to form the touch display panel. A user can touch objects displayed on the touch display panel with his or her finger or a touch pen to input information or perform an operation.

Please refer to FIG. 6. FIG. 6 is a sectional view of a conventional touch display panel. As illustrated in FIG. 6, in the prior art, a touch panel 6 is disposed between a display panel 2 b and a lens 5. A black layer 51 is provided on the periphery of a lower surface of the lens 5. The black layer 51 is stuck to the periphery of the upper surface of the touch panel 6. There is a stick layer 4 c disposed between the black layer 51 and the touch panel 6, as shown in FIG. 6. For the conventional touch panel 6, conductive lavers are formed on the upper surface of a glass substrate 61. The conductive layers include at least a lower transparent conductive layer 62 and an upper transparent conductive layer 65. The conductive layers may include but not be limited to an indium-tin-oxide (ITO) material. A transparent insulation layer 64 is formed between the upper transparent conductive layer 65 and the lower transparent conductive layer 62. On each periphery of the upper transparent conductive layer 65 and the periphery of the lower transparent conductive layer 62, a metal trace 63 is formed respectively for transmitting signals thereon. The black layer 51 is arranged to cover the metal traces 63 so that the metal traces 63 are not exposed when viewed from above the lens 5 for prettifying the appearance of the lens 5. A transparent overcoat 66 made of insulation material (such as silicon nitride, silicon dioxide, etc.) is formed above the upper transparent conductive layer 65 to prevent the upper transparent conductive layer 65 from being scraped and damaged. The coordinates of a position that has been touched on the touch panel 6 is obtained according to detection of an induced current corresponding to a capacitive generated between the transparent conductive layers 62 and 65 and the human body.

The display panel 2 b may include a liquid crystal display (LCD) formed by providing a liquid crystal layer 24 b between an upper glass substrate 22 b and a lower glass substrate 26 b. An upper polarizing plate 21 b is provided on a top surface of the upper glass substrate 22 b, and a transparent conductive layer 23 b is provided between the liquid crystal layer 24 b and a bottom surface of the upper glass substrate 22 b. A lower polarizing plate 27 b is provided on a bottom surface of the lower glass substrate 26 b. Another transparent conductive layer 25 b is provided between the liquid crystal layer 24 b and a bottom surface of the lower glass substrate 26 b. The upper glass substrate 22 b and the transparent conductive layer 23 b form an upper glass electrode substrate. The lower glass substrate 26 b and the transparent conductive layer 25 b form a lower glass electrode substrate. The display panel 2 b and the touch panel 6 are laminated together with a stick layer 4 b disposed between them.

As illustrated in FIG. 6, the liquid crystal layer 24 b is sandwiched between the upper glass electrode substrate and the lower glass electrode substrate. Driven by an electric field between the upper glass electrode substrate and the lower glass electrode substrate, the liquid crystal molecules contained by the liquid crystal layer 24 b are twisted to determine whether light from a light source can pass through. Further, the liquid crystal display displays a colorful image using a color filter for the upper glass substrate 22 b. A user then may see an image from the top of the lens 5. The user then is able to perform an operation or input information by touching the lens 5 with the indication conveyed by the image.

As described above, in the prior art, each of the lens 5 and the touch panel 6 is formed on a glass substrate separately and individually, wherein the glass substrate 61 of the touch panel. is individually shown in FIG. 6. After separate and individual fabrication, the lens 5 and the touch panel 6 are then laminated. Each of the lens 5 and the glass substrate 61 of the touch panel 6 is made of same glass material, which increases the consumption of glass material in production of the touch display panel. Besides, the assembling process is very complex and time wasting, and it is easy to generate defective products during the lamination process. Furthermore, the thickness of the touch display panel is hard to reduce for both the lens and the touch panel adopt the glass substrates.

In view of the foregoing, there is a need for a capacitive touch panel that can alleviate the aforementioned disadvantages.

BRIEF SUMMARY OF THE INVENTION

One object of the invention is to provide an integrally-formed capacitive touch panel which has a low cost, a high yield rate and a simplified assembling process.

Another object of the invention is to provide a integrally-formed slim-type capacitive touch panel.

An exemplary embodiment of the integrally-formed capacitive touch panel is disclosed comprising: a singular lens substrate having a first surface and a second surface, a mask layer. and a sensing circuit integrally coupled with said singular lens substrate. Said singular lens substrate, said mask layer, and said sensing circuit are integrally formed.

An exemplary embodiment of the integrally-formed slim-type capacitive touch panel is disclosed comprising: a singular substrate having a top surface for receiving physical tactile input and a bottom surface, a mask layer, and a sensing circuit. Said mask layer and said sensing circuit are integrally formed on the bottom surface of said singular substrate.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an electronic device with a capacitive touch panel of the invention;

FIG. 2 is a sectional view of a touch display panel including a capacitive touch panel according to an exemplary embodiment of the invention;

FIG. 3 is a sectional view of a touch display panel including a capacitive touch panel according to an exemplary embodiment of the invention;

FIG. 4 is a sectional view of a touch display panel including a capacitive touch panel according to an exemplary embodiment of the invention;

FIG. 5 is a sectional view of a touch display panel including a capacitive touch panel according to an exemplary embodiment of the invention; and

FIG. 6 is a sectional view of a touch display panel according to the prior art.

DETAILED DESCRIPTION

FIG. 1 is a perspective view showing an electronic device with an integrally-formed capacitive touch panel 1 of the invention. The capacitive touch panel 1 is assembled in a shell 3 of the electronic device, as illustrated in FIG. 1. FIG. 2 is a sectional view showing the capacitive touch panel 1 disposed on a display panel 2 according to one exemplary embodiment of the invention. In the present invention, the capacitive touch panel 1 includes a singular substrate 11, a mask layer 12 and a sensing circuit 13. The singular substrate 11. the mask layer 12 and the sensing circuit 13 are integrally formed. Therefore, there is no need to adopt other substrates for the integrally-formed capacitive touch panel 1, and there is no need to perform lamination in the assembly of the present touch panel as required in the conventional touch module. The details are illustrated as below.

The singular substrate 11 may be made of glass material to form a singular lens substrate. The singular substrate 11 may be otherwise made of plastic material, which includes but is not limited to rubber and ebonite. The singular substrate 11 includes a top surface 111 for receiving physical tactile input and a bottom surface 112 of the singular substrate 11.

The mask layer 12 is integrally formed on the bottom surface 112 of the singular substrate 11, and the mask layer 12 may he a black resist or other opaque coating layer. A smooth layer 15 is provided on one side of the singular substrate 11, as illustrated in FIG. 2. In the fabrication process according to the present invention, the smooth layer 15 is provided such that the lower surface of the mask layer 12 may be smoothed and the sensing circuit 13 grown thereon may be flatter. The yield rate of the final product of the touch panel 1 can be enhanced in accordance. The smooth layer 15 may be made of transparent organic or inorganic material. Please be noted that the smooth layer 15 is optional in the present invention. The structure illustrated in FIG. 2 is only exemplary.

As illustrated in FIG. 2, part of the sensing circuit 13 is grown on a bottom surface of the mask layer 12, hence, when viewed from above the singular substrate 11, it appears that that part of the sensing circuit 13 is “covered” by the mask layer 12. The exposed part of the sensing circuit 13, that is, the part of the sensing circuit 13 that is not grown under the mask layer 12, forms a sensing region 14.

The effective range of the sensing region 14 includes the area marked in FIG. 2 and FIG. 3. In the sensing region 14, the sensing circuit 13 is not grown on the bottom surface of the mask layer 12 but on a lower surface of the smooth layer 15. According to an exemplary embodiment of the present invention, a shielding layer 16 may be provided on the bottom surface of the singular substrate 11, and the mask layer 12 is grown thereon. The shielding layer 16 may prevent noise signals.

The sensing circuit 13 may be formed by coating, exposing, developing and etching. In one of the exemplary embodiments, the sensing circuit 13 includes a conductive electrode 131. The sensing circuit 13 may further include a metal trace 132, as shown in FIG. 2. The metal trace 132 can be arranged on the top surface of the conductive electrode 131. Please refer to FIG. 3. FIG. 3 is a sectional view of a touch display panel including a capacitive touch panel according to another exemplary embodiment of the invention. As illustrated in FIG. 3, a metal trace 133 is arranged on the bottom surface of the conductive electrode 131. The metal trace 132 in the embodiment shown in FIG. 2 and the metal trace 133 in the embodiment shown in FIG. 3 are both “covered” by the mask layer 12 from a view above the singular substrate 11. Because from above the singular substrate 11 the metal traces 132 and 133 are not exposed, the appearance of the singular substrate 11 is improved.

The conductive electrode 131 is usually made of transparent conductive material (such as indium tin oxide (ITO)). An overcoat 17 as shown in FIG. 2) is coated on the lower surface of the sensing circuit 13. An adhesive layer 4 is provided between the integrally-formed capacitive touch panel 1 and the periphery of the display panel 2. In one exemplary embodiment as shown in FIG. 2, the adhesive layer 4 is provided between the overcoat layer 17 and the display panel 2, while the overcoat 17 may he omitted in other embodiments, as shown in FIG. 3, for example, and the adhesive layer 4 is directly arranged between the sensing circuit 13 and the display panel

According to the present invention, when the top surface 111 of the singular substrate 11 receives a physical tactile input, the conductive electrode 131 in the sensing region 14 outputs. a capacitive sensing signal corresponding to the touched position for a capacitive effect is produced by the physical tactile input received by the top surface 111 of the singular substrate 11. The capacitive sensing signal is transmitted along the metal trace, 132 or 133, to a processor (not shown) for detecting/calculating the coordinates of the touched position.

In the present invention, within the touch panel, the lens and the sensing circuit share the same singular substrate and are integrally formed. Thus, substrates conventionally utilized for the lens and the touch panel separately can be reduced. Therefore, the bonding and lamination process in the conventional touch display panel fabrication can be simplified. The cost and time for producing the touch panel can be reduced and the touch panel can also be of a slim type design.

FIG. 4 is a sectional view showing the capacitive touch panel 1 a assembled on a display panel 2 a according to another embodiment of the invention. The capacitive touch panel 1 a includes a singular lens substrate 11 a, a mask layer 12 a, a first sensing circuit 13 a, an insulation layer 18 a and a second sensing circuit 19 a. According to the invention, the singular lens substrate 11 a, the mask layer 12 a, the first sensing circuits 13 a, the insulation layer 18 a and the second sensing circuit 19 a of the capacitive touch panel la are integrally formed.

The singular lens substrate 11 a may be made of different transparent material. The singular lens substrate 11 a includes a top surface 111 a for receiving physical tactile input and a bottom surface 112 a.

The mask layer 12 a is provided on the bottom surface 112 a of the singular lens substrate 11 a. The mask layer 12 a may be a black resin or other opaque coating material.

The first sensing circuit 13 a is grown on the singular lens substrate 11 a and the mask layer 12 a. The smooth layer 15 a, made of transparent organic or inorganic material, is provided on the singular lens substrate 11 a in some of the exemplary embodiments of the present invention such that the first sensing circuit 13 a grown thereon may he flatter. Please note that the smooth layer 15 a is optional in the present invention and may be omitted in different embodiments. As illustrated in FIG. 4, partial of the first sensing circuit 13 a is grown on a bottom surface of the mask layer 12 a, hence, when viewed from above the singular lens substrate 11 a, it appears that that part of the first sensing circuit 13 a is “covered” by the mask layer 12 a. The exposed part of the first sensing circuit 13 a, that is, the part of the first sensing circuit 13 that is not grown under the mask layer 12 a, forms a sensing region 14 a. When a physical tactile input is received by the top surface 111 a, the first sensing circuit 13 a may output a first axial sensing signal and the second sensing circuit 19 a may output a second axial sensing signal in accordance.

The insulation layer 18 a is provided to insulate the first sensing circuit 13 a and the second sensing circuit 19 a. The two sensing circuits 13 a and 19 a are orthogonal to each other. Therefore, the insulation layer 18 a is used to electrically insulate the first sensing circuit 13 a and the second sensing circuit 19 a. The insulation layer 18 a may be fully distributed between the two sensing circuits or only in some area to prevent the contact of first sensing circuit 13 a and the second sensing circuit 19 a in the intersection area.

According to an exemplary embodiment of the present invention, a shielding layer 16 a may be provided on the bottom surface of the singular lens substrate 11 a, and the mask layer 12 a is further grown thereon. The shielding layer 16 a may introduce prevention of noise signals. In some exemplary embodiments, the width of the shielding layer 16 a may be equal to the width of the mask layer 12 a.

In one of the exemplary embodiments, the first sensing circuit 13 a includes a conductive electrode 134 a. The first sensing circuit 13 a may further include a metal trace 132 a arranged on the conductive electrode 134 a. As illustrated in FIG. 4, the metal trace 132 a may be arranged on the top surface of the conductive electrode 134 a. Please refer to FIG. 5. FIG. 5 is a sectional view of a touch display panel including a capacitive touch panel according to another exemplary embodiment of the invention. As shown in FIG. 5, the metal trace 133 a may be arranged on the bottom surface of the conductive electrode 134 a. The metal trace 132 a in the embodiment shown in FIG. 4 and the metal trace 133 a in the embodiment shown in FIG. 5, when viewed from above (e.g., above the singular substrate 11 a) are both “covered” by the mask layer 12 a. Because when viewed from above the singular substrate 11 a, the metal traces 132 a and 133 a are not exposed, the appearance of the singular lens substrate 11 a is improved.

The second sensing circuit 19 a includes a conductive electrode 134 h. In one of the exemplary embodiments, the second sensing circuit 19 a may further include a metal trace 132 b arranged on the conductive electrode 134 b. As illustrated in FIG. 4, the metal trace 132 b may be arranged on the top surface of the conductive electrode 134 b. In another exemplary embodiment shown in FIG. 5, the metal trace 133 b may be arranged on the bottom surface of the conductive electrode 134 b. Similarly, the metal trace 132 b in the embodiment shown in FIG. 4 and the metal trace 133 b in the embodiment shown in FIG. 5 are both “covered” by the mask layer 12 a when viewed from above the singular lens substrate 11 a. The metal traces 132 b and 133 b are not visually exposed when viewed from above the singular lens substrate 11 a.

An adhesive layer 4 a is provided between the capacitive touch panel 1 a and the display panel 2 a. In the exemplary embodiment shown in FIG. 4, an overcoat 17 a is selectively further included and integrally formed on the bottom surface of the second sensing circuit 19 a. As shown in FIG. 5, the overcoat 17 a is omitted, and the adhesive layer 4 a is directly bonded to the second sensing circuit 19 a and the display panel 2 a.

According to the present invention, when the top surface 111 a of the singular lens substrate 11 a in the sensing region receives a physical tactile input, each of the conductive electrode 134 a and the conductive electrode 134 b outputs a capacitive sensing signal corresponding to the touched position, respectively. The capacitive sensing signals are transmitted along the corresponding metal traces to a processor (not shown) for detecting/calculating the coordinates of the touched position.

In the present invention, within the capacitive touch panel, the lens, the mask layer and the sensing circuit share the same singular substrate and are integrally formed. The mask layer and the sensing circuit may be formed on the same side of the singular substrate, as illustrated in previous exemplary embodiments of the invention. However, in the present invention, it is possible to form the mask layer and the sensing circuit on the opposite side of the singular substrate. In other embodiments, the sensing circuit of the present invention may be coupled with the singular substrate and/or the mask layer. In still the other embodiments of the present invention, the mask layer and the sensing circuit may be integrally formed on the bottom surface of said singular substrate. According to the present invention, the substrates conventionally provided for the lens and the touch panel separately can be reduced. Therefore, the lamination process in the conventional touch display panel fabrication can be simplified. The cost and time for producing the touch panel can be reduced, and the size of the capacitive touch panel can be reduced.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. 

What is claimed is:
 1. An integrally-formed capacitive touch panel, comprising: a singular lens substrate having a top surface for receiving physical tactile input and a bottom surface ; a mask layer; and a sensing circuit integrally coupled with said bottom surface of said singular lens substrate, wherein said sensing circuit and said mask layer are integrally formed on said bottom surface of said singular lens substrate, and said sensing circuit is a single layer circuit.
 2. The integrally-formed capacitive touch panel of claim 1, wherein said sensing circuit is coupled with said mask layer.
 3. The integrally-formed capacitive touch panel of claim 1, wherein said mask layer is formed on the periphery of said bottom surface of said singular lens substrate.
 4. The integrally-formed capacitive touch panel of claim 3, wherein said mask layer is made of black resist.
 5. The integrally-formed capacitive touch panel of claim 1, further comprising: a shielding layer formed on the periphery of said singular lens substrate, wherein said shielding layer is positioned between said singular lens substrate and said mask layer.
 6. The integrally-formed capacitive touch panel of claim 5, wherein the width of said shielding layer is substantially equal to the width of the mask layer.
 7. The integrally-formed capacitive touch panel of claim 1, wherein said sensing circuit comprises a conductive electrode and a metal trace.
 8. The integrally-formed capacitive touch panel of claim 7, wherein said mask layer covers areas covered by said metal trace..
 9. The integrally-formed capacitive touch panel of claim 8, wherein said metal trace is formed on a surface of said mask layer.
 10. The integrally-formed capacitive touch panel of claim 7, wherein said conductive electrode outputs a capacitive sensing signal corresponding to a touched position for a capacitive effect produced by said physical tactile input on the first surface of said singular substrate.
 11. The integrally-formed capacitive touch panel of claim 10, wherein said capacitive sensing signal is transmitted along, said metal trace to a processor for detecting/calculating the coordinates of the touched position.
 12. The integrally-formed capacitive touch panel of claim 1, further comprising: an overcoat integrally formed on a surface of said sensing circuit.
 13. The integrally-formed capacitive touch panel of claim 1, wherein said integrally-formed capacitive touch panel is capable of being disposed on a display panel.
 14. The integrally-formed capacitive touch panel of claim 1, further comprising: a shielding layer formed on the periphery of said singular lens substrate, said shielding layer is positioned between said singular lens substrate and said mask layer: wherein said mask layer is formed on the periphery of said bottom surface of said singular lens substrate through said shielding layer.
 15. An integrally-formed capacitive touch panel. comprising: a singular lens substrate haying a top surface for receiving physical tactile input and a bottom surface; a mask layer; and a sensing circuit integrally coupled with said bottom surface of said singular lens substrate, wherein said sensing circuit is integrally formed on said bottom surface of said singular lens substrate and said mask layer is formed on said top surface of said singular lens substrate: and said sensing circuit is a single layer circuit.
 16. An integrally-formed capacitive touch panel, comprising,: a singular lens substrate having a top surface for receiving physical tactile input and a bottom surface; a mask layer; and a sensing circuit integrally coupled with said bottom surface of said singular lens substrate; a smooth layer disposed between said singular lens substrate and said sensing circuit; wherein said sensing circuit said mask layer and said smooth layer are integrally formed on said bottom surface of said singular lens substrate, and said sensing circuit is a single layer circuit.
 17. The integrally-formed capacitive touch panel of claim 16, wherein said sensing circuit is coupled with said mask layer.
 18. The integrally-formed capacitive touch panel of claim 6, wherein said smooth layer is made of transparent organic or inorganic material.
 19. The integrally-formed capacitive touch panel of claim 16, wherein said mask layer is formed on the periphery of said bottom surface of said singular lens substrate.
 20. The integrally-formed capacitive touch panel of claim 16, further comprising: a shielding layer formed on the periphery of said singular lens substrate, wherein said shielding layer is positioned between said singular lens substrate and said mask layer.
 21. The integrally-formed capacitive touch panel of claim 20, wherein the width of said shielding layer is substantially equal to the width of the mask layer.
 22. The integrally-formed capacitive touch panel of claim 16, wherein said sensing circuit. comprises a conductive electrode and a metal trace.
 23. The integrally-formed capacitive touch panel of claim 22, wherein said mask layer covers areas covered by said metal trace.
 24. The integrally-formed capacitive touch panel of claim 23, wherein said metal trace is formed on a surface of said mask layer.
 25. The integrally-formed capacitive touch panel of claim 22, wherein said conductive electrode outputs a capacitive sensing signal corresponding to a touched position for a capacitive effect produced by said physical tactile input on the first surface of said singular substrate.
 26. The integrally-formed capacitive touch panel of claim 25, wherein said capacitive sensing signal is transmitted along said metal trace to a processor for detecting/calculating the coordinates of the touched position.
 27. The integrally-formed capacitive touch panel of claim 16, further comprising: an overcoat integrally formed on a surface of said sensing circuit.
 28. The integrally-formed capacitive touch panel of claim 16, wherein said rally-formed capacitive touch panel is capable of being disposed on a display panel.
 29. The integrally-formed capacitive touch panel of claim 16, further comprising,: a shielding layer formed on the periphery of said singular lens substrate, said shielding layer is positioned between said singular lens substrate and said mask layer; wherein said mask layer is funned on the periphery of said bottom surface of said singular lens substrate through said shielding layer.
 30. An integrally-formed capacitive touch panel, comprising: a singular lens substrate haying a top surface for receiving physical tactile input and a bottom surface; a mask layer; and a sensing circuit integrally coupled with said bottom surface of said singular lens substrate; a smooth layer disposed between said singular lens substrate and said sensing circuit; wherein said sensing circuit and said smooth layer are integrally formed on said bottom surface of said singular lens substrate, and said mask layer is formed on said top surface of said singular lens substrate; and said sensing circuit is a single layer circuit. 